Posted
by
Soulskill
on Friday August 16, 2013 @05:12PM
from the does-graphene-even-lift? dept.

New submitter Dialecticus writes "Sebastian Anthony at ExtremeTech has written an article about research into the physical properties of carbyne, an elusive form of carbon. A new mathematical analysis by Mingjie Liu and others at Rice University suggests that carbyne may achieve double the strength of graphene, stealing its crown and becoming the strongest material known to man. 'While carbyne cannot be stretched, it can be bent into an arc or circle — and by doing so, the additional strain between the carbon atoms alters the electrical bandgap. This property could lead to some interesting uses in microelectromechanical systems (MEMS). By adding different molecules to the end of a carbyne chain, such as a methylene (CH2) group, carbyne can also be twisted — much like a strand of DNA — again adding strain and modifying the electrical bandgap. By "decorating" carbyne chains with different molecules, other properties can be added, too: Tack some calcium atoms on the end, which like to mop up spare hydrogen molecules, and suddenly you have a high-density, reversible hydrogen storage sponge.
It’s also important to note that, just like graphene, carbyne is just one atom thick. This means that, for a given mass of carbyne, its surface area is relatively massive. A single gram of graphene, for example, has a surface area of about five tennis courts. This could be very important in areas such as energy storage (batteries, supercapacitors), where the surface area of the electrode is directly proportional to the energy density of the device.'"

I guess it's hard to say when a breakthrough will happen. Progress tends to be very incremental. When I was much younger, I was promised that flying cars, flat screen TVs you could hang like a painting and fusion would be "a few years" at most.

Took over 30 yrs just for the TVs, fusion, er, well, "somewhat more than a few years" and counting and the flying cars, well, I suppose we could make them happen very soon if you've got megabucks to spend.

You get your exoskeleton as soon as battery density increases, or generator+turbine volume decreases. If you;re happy with a tether, the XOS2 (and countless other research devices) work just fine right now.

Well, there is a lot of issues here.1. Nano-technology needs a lot of money for research and development. Most companies do not want to fund in R&D as they cannot quantify the value.2. Governments are trying to show that they are responsible with money so they are not funding R&D because they will get on some media expose on how they are wasting their money playing with pencil lead and scotch tape.3. Colleges are getting tight on R&D because there is pressure to cut college costs down.

Acetylene features the single & triple carbon bonds. It burns so hot because these bonds are inherently unstable. So how is it that this new substance, with these more-unstable-than-normal-carbon bonds, supposedly *stronger*?

The -yne ending is already in common use for carbon compounds with a triple bond. For example, ethyne (the IUPAC systematic name for acetylene). It's not a very good name in this case though- "carbyne" already refers to a type of reactive species of carbon with three unpaired electrons, in analogy to the more common "carbene" which has two unpaired electrons. Wikipedia suggests a better name for the carbon chain to be "linear acetylenic carbon," though I'll admit it doesn't roll off the tongue. Shorter vers

From the non-chemistry side of the etymology, it is apparently not known with certainty why a short rifle is called a carbine [etymonline.com] in the first place:

short rifle, 1580s, from French carabine (Middle French carabin), used of light horsemen and also of the weapon they carried, of uncertain origin, perhaps from Medieval Latin Calabrinus "Calabrian" (i.e., "rifle made in Calabria"). A less-likely theory (Gamillscheg, etc.) connects it to Old French escarrabin "corpse-bearer during the plague," literally (probably) "

But you're not describing a structure that stretches; you're describing one that telescopes. Not the same thing.

And while a space elevator won't be fixed at both ends the way a bridge is, it's still going to be subject to outside forces acting on it (high-speed winds in the upper atmospheres, for example). If the bridge parallel bothers you, consider a skyscraper instead - and skyscrapers also need to be elastic enough to sway a little bit.

I highly doubt we'll ever be able to make strands of this stuff several thousands of km long, so shorter strands will have to be combined. The epoxy or whatever is used to hold them together will undoubtedly have some stretch.

Also, carbon bonds may not be particularly stretchy, but over that kind of length even a tiny amount will add up to a decent distance. If that's not enough, use the helical form.

Instability in organic molecules does not neccessarily mean that it reacts with gasses in the air (namely oxygen).

It usually means that there's a more stable form it will inevitably convert to. There are countless conversion reactions in organic molecules - exposure to heat, air or light usually only fastens the process. Preventing exposure to these factors does not stop the degradation, however.

Take batteries as an example. LiIon batteries will degrade regardless of outside factors - and those are pretty m

An straight-up Space Elevator is still way beyond us, even if we could pump out molecularly perfect nanotubes of indefinite length. But smaller tether systems are totally possible; 'stationary' and hypersonic Bolos and Skyhooks, depending on the orbital velocity and tip velocity (itself depending on tether length and rotation rate). You don't need a massive anchor site, you could fly some of the smaller ones in a single launch, and we could make some of the smaller ones with materials we already manufacture

As a mechanical engineer, I have only ever needed integral calculus outside of school work (including tutoring) three times:1. With a friend, for fun, to win a bet. Yay, free beer!2. To answer a particular question for work. Yay, happy boss!3. Just now, for fun, to determine the required material stiffness for a cable hanging down from geostationary orbit (i.e. a space elevator cable) to support its own weight. Yay, Science!

You got to think 2 dimensionally! Think of having a bunch of sphere magnets, you clip them into a 1 magnet high sheet. Now you can bend the sheet of magnets without stretching them they just roll on each other. You pole is more 3 dimension so you have rows and rows of these things so the upper part will stretch assuming that its bonds are equal on all dimensions.

Perhaps a little more emphasis should be given to the fact that the compound in question has never been synthesized, despite decades of effort. And that one strand would combine explosively with a second, if two such strands could be made.

Normally, one could measure the inner surface and the outer and compare. You could use any unit of measurement you wanted, such as "atom lengths". For example, you could say that the inner surface is a million atoms long and the outer surface is a 1.03 million.

This stuff is one atom thick. In this case, the atoms that make up the inner surface are SAME ATOMS as the outer surface. The inside and the outside are the same side! So of course they are the same length, since they are the same atoms.